Surgical site infections (SSI) occur following about 2-3 percent of surgeries in the United States with an estimated 500,000 incidents of SSI occurring annually, which can lead to significant patient morbidity and mortality. In addition to the negative impact of such infections on patient health, these potentially avoidable infections contribute significantly to the financial burden experienced by the health care system. SSIs result when an incision becomes contaminated by bacteria, and for most surgeries the primary source of these infection-causing microorganisms is the skin (an exception being surgeries in which the gastrointestinal tract is penetrated).
Various compositions are used to prepare the skin prior to surgery. Skin preparations or “preps” are used to remove some level of microbial load on the skin prior to making an incision. Skin sealant materials are used to protect patients from bacterial infections associated with surgical site incisions and insertion of intravenous needles. Skin preps are applied to the skin and allowed to dry to maximize effectiveness for reducing microorganisms. After the skin prep has dried, the sealant may be applied directly to the skin in liquid form. The sealant forms a coherent film with strong adhesion to the skin through various techniques based on the chemistry of the sealant composition.
Skin preps currently are predominantly povidone-iodine or chlorhexidine gluconate based formulations and may contain alcohol for fast drying and more effective killing of organisms. Time constraints in the operating room and the lack of an indicator that the prep has dried often result in the skin remaining wet when draping and/or surgery begin, creating the possibility of infection.
Skin sealants now use a polymer composition that dries to form a film through evaporation of a solvent, for example. Other skin sealants contain monomeric units that polymerize in situ to from a polymeric film. Cyanoacrylate sealants containing 2-cyanoacrylate monomer are an example of the latter type wherein the monomer polymerizes in the presence of a polar species such as water or protein molecules to form an acrylic film. The resulting film formed serves to immobilize bacterial flora found on the skin and prevents their migration into an incision made during a surgical procedure or skin puncture associated with insertion of an intravenous needle.
In some cases, a skin sealant may also encompass substances designed to protect or treat the nails or mucosal surfaces of the body. Such substances include nail polish, eyedrops, nasal sprays, etc and serve to provide an additional barrier between the skin and the environment.
Skin sealants may contain additives such as plasticizing agents to improve film flexibility and conformance, viscosity modifiers to aid in application of the liquid composition, free radical and anionic scavengers to stabilize the product prior to use, biocidal agents to kill immobilized bacteria under the film, and the like.
Skin sealants are conventionally placed in dispensers or applicators until they are needed. One exemplary applicator has the liquid sealant held in at least one oblong glass ampoule within a rigid nylon housing. The housing has a body and a cap that are slidably connected and it is the cap which holds the ampoule(s). In use, the two parts are moved toward each other to dispense the liquid; the cap moving into the body. Moving the parts together results in breakage of the glass ampoule(s) and dispensing of the liquid. A detent-type locking mechanism holds the body and cap together once they are moved. The locking mechanism consists of slots formed in the cap into which fits a slight protuberance or knoll of plastic formed on the inside surface of the body. Once the ampoule is broken, the liquid travels through a small piece of foam which catches any glass shards that may have been formed by the breakage of the ampoule and thence on to the tip portion of the body. The tip has a number of small holes in it to allow the liquid to pass through. The body of the tip has a piece of foam or sponge on the outside, which is often held in place with a rigid plastic oval-shaped ring that snaps in place on the tip. The outer foam contacts the skin of the patient when the liquid is dispensed. Other types of applicators or dispensers may be found in U.S. Pat. Nos. 7,094,250, 4,854,760, 4,925,327 and 5,288,159, and U.S. Patent Application Publication Nos. US2007/0147947 and 2008/0046004, all of which are incorporated herein by reference for all purposes.
In using the applicator, a user positions the dispensing end, which has the foam or sponge saturated with skin sealant, against a selected area of a patient's prepped skin. Stroking the dispensing end against the patient's skin, a user disposes the skin sealant thereon. It is desirable to uniformly apply the liquid skin sealant to the skin so that a uniform layer is formed on the skin to protect an incision, and so forth, from the migration of bacterial flora from the skin to the incision. There are several problems, however, with existing dispensing ends which can negatively impact the skin sealant's ability to immobilize bacterial flora found on the skin and prevent their migration into an incision made during a surgical procedure, a skin puncture associated with insertion of an intravenous needle, or a wound.
The dispensing end of the applicator is generally relatively rigid. Such rigidity works reasonably well on a relatively flat surface, such as a patient's abdomen. Problems occur, however, when using the applicator to apply skin sealant to angles, convexities, concavities, and so forth, such as those which are present about a bended knee, bended elbow, fingers, and so forth. In this instance, because of the rigidity of the dispensing end of the applicator, a smooth, even and regular layer of skin sealant is very difficult or impossible to apply. This is due to the fact that the dispensing end of the applicator does not flex or bend sufficiently to permit the application of the skin sealant evenly and uniformly into concave areas, such as behind a bended knee, or convex areas, such as over and around a knee cap, and so forth. Therefore, coverage by the skin sealant is likely to be non-uniform, therefore reducing the ability of the skin sealant to trap and immobilize bacterial flora. Further, the rigid dispensing end of the applicator, when used aggressively by a user over a convex or concave area, may create small scrapes or abrasions, even though the dispensing end may be covered by a foam or sponge. Such abrasions permit bacterial flora trapped on the skin below the skin sealant to migrate into the body via such abrasions. Further, the dispensing end, due to the sponge or foam on the dispensing end, cannot be used over sutures or staples covering an incision. This is due to the foam or sponge catching upon and pulling the sutures or staples. When pulled, the suture line may open slightly, again permitting an introduction of bacterial flora into the wound.
Therefore, there is a need for a dispensing end of a skin sealant applicator which is sufficiently flexible, so that skin sealant may be easily applied to concave and/or convex areas on a patient's body. Further, there is a need for a dispensing end on a skin sealant applicator which prevents abrasion of a patient's skin by over-zealous application of the skin sealant therein, or by application of too much pressure against the skin combined with a sharpness of a tip on the dispensing end. Further, such a liquid applicator would desirably provide a smooth and even distribution of the skin sealant over the chosen skin surface. Finally, there is a need for a dispensing end of a skin sealant applicator for skin sealant which permits the application of the skin sealant over an insertion site of a needle or an incision closed by sutures and/or staples, without catching or pulling the sutures or staples.